It is believed that the earliest feature of chronic bronchitis is excessive secretary activity of the mucous glands and goblet cells in response to the inhalation, for a prolonged period, of irritant substances in dust, smoke or fumes.

• 一般认为，慢性支气管炎的最早期特征是，由于长期吸入灰尘和烟雾中刺激物质而引起的粘液腺和杯形细胞的过强分泌活动。